Some electric power systems in various households and industry may be split-phase electric power systems. A split-phase power system is a type of single-phase power system that may comprise two alternating current (AC) voltage lines. The AC voltage lines may have a common neutral line. The AC voltage amplitude and/or root mean square (RMS) value with respect to the neutral line may be about half of the AC voltage amplitude and/or RMS value between the AC voltage lines, i.e., line-to-neutral voltage amplitude and/or RMS value may be about half of the line-to-line voltage amplitude and/or RMS value. In a split-phase system providing power to balanced loads, (i.e., where the loads coupled between each AC voltage line and the neutral line are about the same), the sum of the instantaneous currents of the two lines may be about zero, i.e., the current flowing through the neutral line may be significantly smaller than the current flowing through the AC voltage lines.
Other electric power systems may be three-phase electric power systems. A three-phase power system has three power lines, each having an alternating current of the same frequency and voltage amplitude and/or RMS value with respect to a neutral line. Each power line has a phase shift of one third of the period with respect to the other two lines. In a three-phase system feeding balanced loads, the sum of the instantaneous currents of the three lines may be about zero.